In recent years, the increased costs of metal containers has forced the packaging industry to use corrugated cartons having plastic bag liners for packaging food products, perishables and other consumer commodities which have heretofore been packed in metal containers. While mechanical devices are known in the art and are used for forming corrugated cartons from flat unformed cartons, no satisfactory apparatus has heretofore been successfully developed for forming the carton with a thin interior plastic bag liner. Accordingly, it has been necessary to additionally employ numerous individuals whose sole function is to insert these liners in the cartons after they have been formed. This additional step significantly increases the costs of packaging these materials. It would be highly desirable to provide an apparatus capable of inserting the plastic bag liner within the carton during the formation of the carton and thereby eliminate the added expense of having to insert those bags by hand.